This proposal will investigate the reasons for the striking declines in cardiovascular mortality. This will be accomplished using data collected since 1965 by the Human Population Laboratory on two large representative populations which have been prospectively followed for mortality. Information collected in 1965 and 1974 for one cohort and in 1974 for another, coupled with mortality information for both of these cohorts through 1982, will allow us to examine the impact of risk factors and changes in risk factors on mortality declines. Risk factors to be considered fall into the following domains: Discretionary Behaviors (smoking, alcohol consumption, relative weight, physical activity levels, eating practices); Social Network Participation; Psychological Functioning; Demographic Status; Medical Care Utilization, and Physical Health Status. Significantly, this will be accomplished using data collected on samples of individuals representative of Alameda County at two points in time which span the period of declining mortality. Results will provide preliminary evidence concerning the reasons for declines in mortality which will prove useful in further examination of these declines using community surveillance.